1. Field of the Invention
The present invention relates to a system and method for controlling auto-ignition combustion of gasoline in an internal combustion engine, and an auto-ignition type internal combustion engine.
2. Description of Related Art
In auto-ignition combustion of gasoline fuel, burning velocity and/or combustion initiation determine combustion event. JP-A 10-196424 discloses a technique to adjust combustion initiation time at around top dead center (TDC) of exhaust stroke of a piston.
The known technique is satisfactory to some extent, however, involves a potential problem that it would be difficult to suppress cost increase due to additional hardware and avoid additional labor and cost for maintenance of such hardware.
Thus, there would be a need for fine and accurate control of combustion event initiated by auto-ignition without relying on such additional hardware.
An object of the present invention is to control combustion event initiated by auto-ignition without any additional hardware to a gasoline internal combustion engine.
In one aspect of the present invention, the above object is accomplished by an auto-ignition type internal combustion engine, comprising:
at least one cylinder;
a fuel injection system performing injection of gasoline fuel for one cycle to create stratified charge in the cylinder;
a sensor generating a sensor signal indicative of combustion event timing of the created stratified charge in the cylinder; and
an engine controller determining an actual value of a characteristic parameter representing combustion event timing in the cylinder from the sensor signal, and modifying at least one operating variables governing injection for the subsequent cycle in such a direction as to decrease a deviation between the actual value of the characteristic parameter and a target value thereof toward zero.